GitLab

- Fix menu bg asset to properly allow the menu to overlap the anchor
- Turn on dismiss button in menu
- Fix some animation code related to the dismiss button in the menu
- Make overlapping an RTL item work properly

BUG=394898
NOTRY=true

Review URL: https://codereview.chromium.org/419673002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@285728 0039d316-1c4b-4281-b951-d872f2087c98